A Multi-Flip-Chip package has one or more flipped semiconductor devices, such as integrated circuit chips and Micro Electro-Mechanical Systems (“MEMS”), that are attached on a substrate via a flip chip bonding process. In a flip chip bonding machine for performing the flip chip bonding process, singulated wafer dice or chips which have been cut and positioned on a wafer table are first picked up by a flip arm. The semiconductor devices are then transferred to a bond head using a “pick-and-flip” operation. After the bond head picks up the semiconductor device, the bond head then attaches the device with its front side containing electrical contacts facing down onto a substrate pad which has been aligned accordingly to receive it.
A flip arm module is used to perform the pick-and-flip operation, and it comprises a picking collet and a flipping mechanism. As the multiple semiconductor devices may have different sizes, different collets will have to be used depending on the different sizes of the semiconductor devices. However, a flip chip bonding machine can conventionally only support one type of collet in the flip arm module. For Multi-Flip-Chip packages, a cascade line system or a dual head system comprising more than one bond head may be utilized to increase throughput. In a cascade line system, two or more individual flip chip bonders are linked through a substrate conveying device. The first flip clip bonder will bond one type of device onto the substrate and then pass the substrate to the second flip clip bonder by way of the substrate conveying device. The second flip chip bonder will be operative to bond another type of semiconductor device on the substrate, and so on if there are more than two flip chip bonders.
In the cascade line system, since two or more machines are connected together, a large footprint is required and malfunction of one machine will affect the overall system performance. Moreover, the two machines have separate optical alignment systems, meaning that different semiconductor devices will be bonded on the aligned pad with different optical alignment systems. This will lead to additional alignment errors and bonding errors due to the misalignment and variation between respective machines. As a result, the bonding accuracy when bonding different types of semiconductor devices will be affected.
In a dual head system, one machine comes with two separate flip arms. A different collet may be installed on each flip arm for handling different types of semiconductor devices in order to assemble Multi-Flip-Chip packages. Different semiconductor devices will be picked and flipped one at a time. Single or dual bond heads may then be used to attach the flipped devices onto the substrate.
However, the dual head system is limited to handling two different types of semiconductor devices only. Also, when one flip arm is operating, the other flip arm is idling since a shared wafer table system is typically used. This affects the utilization of the machine and hence the overall throughput of the machine.